1. Field of the Invention
This present invention relates generally to shelters and to anchoring devices for shelters.
2. Background Information
Temporary shelters are commonly used for recreation, community events as well as in emergencies. In emergencies it is desirable to be able to quickly erect shelters for a variety of purposes. Often emergency shelters are inflated on site. Inflatable shelters have the advantage of being quick to erect and do not require a separate heavy frame. Shelters with inflatable beams give shelter that is quick to erect, strong and that have a maximum area of covered space for the transportation weight. However, inflatable shelters do have problems. The light weight of the shelters gives a shelter that can move easily. One problem with inflatable shelters is that they tend to fill into the shape of a sphere or cylinder like a balloon. Such a shelter has a minimum of usable floor space. Even if heavy objects are placed on the floor of an inflatable shelter to hold the floor down, the upward force of the shelter combined with movement of people in the shelter can cause movement of even fairly heavy objects. Another problem with inflatable shelters is the need for destructive stakes. Stakes are used to tie the structure down to force the inflated structure to have a flat section of floor. This can require a tremendous amount of force and requires a very substantial staking process. Even when staked, there tends to still be unusable space near the walls where the floor still lifts up into a non-flat configuration. Another problem with inflatables is that they can be damaged during the inflation process when they are typically not yet tied down. If inflated on a parking lot, a wind can rake havoc. Another problem with existing inflatable shelters is that the movement of the floors and walls can cause motion sickness to those inside. To solve these problems, the prior art has used tie downs and stakes to secure temporary shelters. However, in emergency situations it is common to erect shelters on pavement such as in a parking lot or even inside a larger building such as a warehouse, gymnasium or sports stadium. In these cases driving stakes into concrete or other floor surfaces is destructive to the facility and also eliminates much of the benefit of an easy to erect building.
A further problem with positively pressured inflatable structures is the tendency for an inflatable shelter to form rounded edges instead of square edges. This tends to yield a floor that does not lay flat all the way to the edges of the floor, rather the edges curl up and as a result usable floor area is reduced. There is often a trip hazard in doorways where the floor of the shelter tends to lift off the underlying surface. Personnel movement on lifted areas result in shelter motion. To correct this problem with the prior art, more staking has been used. To get a truly flat floor it is necessary to stake frequently around the entire perimeter of the structure which greatly increases the time and cost of installation as well as the destructive aspect to the existing concrete surface, floor or pavement. Stake loads increase dramatically with internal pressure on an inflatable shelter. Stresses in the shelter material increase dramatically as the floor/wall interface approaches a sharp corner.
Accordingly, there is a need for an improved method and apparatus to affix a flexible fabric shelter to a surface.